Facts on Desertification a Summary of the Millennium Ecosystem Assessment Desertification Synthesis

Facts on Desertification A Summary of the Millennium Ecosystem Assessment Desertification Synthesis DESERTIFICATION is the persistent degradation of dryland ecosystems. It threatens the livelihoods of some of the poorest and most vulnerable populations on the planet. Desertification is largely caused by unsustainable use of scarce resources. What options exist to avoid or reverse desertification and its negative impacts? Summary written by GreenFacts What is desertification? Desertification is the persistent degradation of dryland ecosystems by variations in climate and human activities. Home to a third of the human population in 2000, drylands occupy nearly half of Earth’s land area. Across the world, desertification affects the livelihoods of millions of people who rely on the benefits that dryland ecosystems can provide. In drylands, water scarcity limits the production of crops, forage, wood, and other services ecosystems provide to humans. Drylands are therefore highly vulnerable to increases in human pressures and climatic variability, especially sub-Saharan and Central Asian drylands. Some 10 to 20% of drylands are already degraded, and ongoing desertification threatens the world’s poorest populations and the prospects of poverty reduction. Therefore, desertification is one of the greatest environmental challenges today and a major barrier to meeting basic human needs in drylands. Desertification affects the world’s most vulnerable populations. How are desertification and human well-being linked? In drylands, more people depend on ecosystem services for their basic needs Desertification affects a wide range of services provided by ecosystems to than in any other ecosystem. Indeed, many of their resources, such as crops, humans: products such as food and water, natural processes such as livestock, fuelwood, and construction materials, depend on the growth of climate regulation, but also non-material services such as recreation, and plants, which in turn depends on water availability and climate conditions. supporting services such as soil conservation. Changes can be quantified and methods are available to prevent, reduce, or reverse them. Fluctuations in the services supplied by ecosystems are normal, especially in drylands, where water supply is irregular and scarce. When faced with desertification, people often respond by making use of However, when a dryland ecosystem is no longer capable to recover from land that is even less productive, transforming pieces of rangeland into previous pressures, a downward spiral of desertification may follow, cultivated land, or moving towards cities or even to other countries. This though it is not inevitable. can lead to unsustainable agricultural practices, further land degradation, exacerbated urban sprawl, and socio-political problems. Who is affected by desertification? Desertification affects the livelihoods of millions of people, as it occurs on all continents (except Antarctica). Desertification takes place in drylands all over the world. Some 10 to 20% of all drylands may already be degraded, but the precise extent of desertification is difficult to estimate, because few comprehensive assessments have been made so far. A large majority of dryland populations live in developing countries. Compared to the rest of the world, these populations lag far behind in terms of human well-being, per capita income, and infant mortality. The situation is worst in the drylands of Asia and Africa. Dryland populations are often marginalized and unable to play a role in decision making processes that affect their well-being, making them even more vulnerable. Desertification has environmental impacts that go beyond the areas directly affected. For instance, loss of vegetation can increase the formation of large dust clouds that can cause health problems in more Desertification processes can lead to the formation of large dust clouds densely populated areas, thousands of kilometers away. Moreover, the that affect air quality and cause health problems thousands of kilometres social and political impacts of desertification also reach non-dryland away (Xinlinhot, China) areas. For example, human migrations from drylands to cities and other countries can harm political and economic stability. What are the major causes of desertification? Desertification is caused by a combination of social, political, economic, and natural factors which vary from region to region. Policies that can lead to an unsustainable use of resources and lack of infrastructures are major contributors to land degradation. Agriculture can play either a positive or a negative role, depending on how it is managed. Policies favoring sedentary farming over nomadic herding in regions more suited to grazing can contribute to desertification. The process of globalization both contributes to desertification and helps prevent it. Studies have shown that, in some cases, trade liberalization, economic reforms, and export-oriented production in drylands can promote desertification. In other cases, enlarged markets outside of the drylands also contribute to successful agricultural improvements. Serious erosion is threatening a farmer’s land Historically, dryland livelihoods have been based on a mixture of hunting, use. Population growth has led to the extension of cultivated lands and gathering, farming, and herding. This mixture varied with time, place, and the irrigation of these lands has brought about desertification, as well as culture, since the harsh conditions forced people to be flexible in land other environmental problems. How would different development paths influence desertification in the future? Population growth and increased food demand are expected to drive continue to be the main factors driving desertification in the near future, the expansion and intensification of land cultivation in drylands. If no and climate change will also play a role. countermeasures are taken, desertification in drylands will threaten future improvements in human well-being and possibly reverse gains in Local adaptation and conservation practices can mitigate some losses of some regions. dryland services, but it will be difficult to reverse losses in terms of biodiversity and in the provision of food and water which is linked to The Millennium Ecosystem Assessment developed four plausible biodiversity. Freshwater scarcity, which already affects 1-2 billion people scenarios to explore the future of desertification and human well-being globally, is expected to increase, causing greater stresses in drylands until 2050 and beyond. The different scenarios are based on either and ultimately a worsening of desertification. increased globalization or increased regionalization, each combined with either a reactive or proactive way of addressing environmental issues. The implementation of the U.N. Convention to Combat Desertification (UNCCD) would be particularly difficult in a regionalized-reactive world (Order In all four scenarios, the desertified area is expected to increase, though from strength scenario), while prospects would improve in a more globalized not at the same pace. Poverty and unsustainable land use practices will world with proactive ecosystem management (TechnoGarden scenario). Map: “Present-day Drylands and their categories How can we prevent or reverse desertification? Effective prevention of desertification requires management and policy approaches that promote sustainable resource use. Prevention should be preferred to rehabilitation, which is difficult and costly. Major policy interventions and changes in management approaches, both at local and global levels, are needed in order to prevent, stop or reverse desertification. Prevention is a lot more cost-effective than rehabilitation, and this should be taken into account in policy decisions. Addressing desertification is critical and essential to meeting the Millennium Development Goals which aim to eradicate extreme poverty and ensure environmental sustainability amongst other objectives. The creation of a “culture of prevention” that promotes alternative livelihoods and conservation strategies can go a long way toward protecting drylands both when desertification is just beginning and when Unsustainable use of resources can contribute to land-degradation. it is ongoing. It requires a change in governments’ and peoples’ Even once land has been degraded, rehabilitation and restoration attitudes. Building on long-term experience and active innovation, measures can help restore lost ecosystem services. The success of dryland populations can prevent desertification by improving agricultural rehabilitation practices depends on the availability of human resources, and grazing practices in a sustainable way. funds, and infrastructures. It requires a combination of policies and technologies and the close involvement of local communities. Is there a link between desertification, global climate change, and biodiversity loss? Desertification diminishes biological diversity, a diversity which contributes to many of the services provided to humans by dryland ecosystems. Vegetation and its diversity are key for soil conservation and for the regulation of surface water and local climate. Desertification also contributes to global climate change by releasing to the atmosphere carbon stored in dryland vegetation and soils. The effect of global climate change on desertification is complex and not yet sufficiently understood. On the one hand, higher temperatures resulting from increased

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